355nm紫外激光器加工多层柔性线路板盲孔

Drilling blind holes on multi-layer FPC board with a 355 nm UV laser

采用输出功率10W的355nmNd:YVO4激光器对4层柔性线路板(FPC)进行了盲孔加工实验。重点研究和分析了不同加工方式、功率密度、扫描间距、开/关激光延时等参数对加工结果的影响。得到的优化工艺参数为:第一次采用加工功率3.9W、频率80kHz、扫描速度50mm/s、开/关激光延时20μs/110μs、扫描间距18μm,第二次将加工功率降到1.4W,其他参数不变,此时,加工盲孔的效果最为理想,重铸层粗糙度为0.88966μm,孔底粗糙度为1.063μm。给出了孔底表面的SEM图和针式台阶仪测量的盲孔底面三维轮廓和切面二维轮廓图。

A 10 W 355 nm Nd：YVO4 laser was used to drill blind holes on multi-layer flexible circuit board（FPC）.The effects of the processing methods and parameters（power density,scan spacing and laser on/off delay） on the micro-drilling quality were investigated and analyzed.Finally,optimization of the processing parameters was achieved.The first group of parameters with laser power of 3.9 W,frequency of 80 kHz,scan speed of 50 mm/s,laser on/off delay of 20 μs/110 μs and scan spacing of 18 μm were adopted;then,the second group of parameters with the power down to 1.4 W and the other parameters were unchanged.At the moment,the effect from drilling blind hole was ideal.The roughness of recast layer and the holes bottom surface measured by surface profile measuring system were 0.889 66 μm and 1.063 μm,respectively.The SEM photograph,the 3D profile of the bottom surface,and the 2D profile of section on the blind hole were all given here.